[vsnet-grb-info 19472] GRB 170604A: optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21192
SUBJECT: GRB 170604A: optical observations
DATE:    17/06/04 20:17:53 GMT
FROM:    Luca Izzo at IAA-CSIC  <Luca.Izzo at ICRA.it>

L. Izzo, A. de Ugarte Postigo, Z. Cano, D.A. Kann (IAA-CSIC) report on behalf of a larger collaboration,

We observed the field of GRB 170604A (Page et al., GCN 21191) with the T27 (Plane Wave CDK 0.70m) of the iTelescope.Net (http://www.itelescope.net) located at Siding Spring, AU.  
A single image of 300 s each was taken in the R and in the V filters, starting at 19:32:07 UT, ~ 1400s after the GRB trigger. We detect a source not visible in PanSTARRS images at RA = 22:50:37.54 DEC = -15:24:44.4 (+- 0.5”) with a preliminary magnitude of R ~ 17.5 (as compared to USNO-B 1.0 field stars), which we consider to be the afterglow. 

An image of the field can be seen at http://goo.gl/Rjmsk6